The following non-descriptive error is being thrown when you bring up the properites of the CDC instance in the Change Data Capture Designer tool if you happen to remove the description that is added to the CDC instance database. You can also get the error when you click on the Oracle or Advanced tabs while the instance is selected in the tool. The service continued to run fine, the error was only occuring while viewing the details of the instance.

"Error occurred while trying to initialize Oracle CDC designer console. <instance name> Additional Information: There is no row at position 0." If you click on the details button on the error dialog you get the following exception details.
There is no row at position 0.
System.IndexOutOfRangeException: There is no row at position 0.
at System.Data.RBTree`1.GetNodeByIndex(Int32 userIndex)
at System.Data.RBTree`1.get_Item(Int32 index)
at System.Data.DataRowCollection.get_Item(Int32 index)
at Attunity.SqlServer.XdbCdcConfig.Core.Managers.CDCM anagerImp.GetInstanceProperties(CDCInstanceInfo cdcInfo)
at Attunity.SqlServer.XdbCdcDesigner.Views.CDCInstanc eView.GetInstanceProperties()

I finally figured out this error was caused by the fact that the description for the SQL Server database, which was added using the "EXECUTE sp_addextendedproperty @name = N'Description'" command had been accidently dropped. Once I manually re-added a description to the DB the error no longer occured. I think the designer console tool needs to be updated to catch this exception and handle it in a cleaner way, providing a more helpful error message.